Note on the results with lower semi-continuity

Yuqing Chen,조열제,Li Yang 대한수학회 2002 대한수학회보 Vol.39 No.4

In this paper, we introduce the concept of lower semi-continuous from above functions and show that many well-known results, such as Ekland's and Caristi's theorems, remain also true under lower semi-continuous from above functions

Effect of Adding Surfactant for Transforming Lignocellulose into Fermentable Sugars during Biocatalysing

Yuqing Zhang,Xuemin Xu,Yuyuan Zhang,Jianfa Li 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.5

Fuel ethanol is one of the most important alternative fuels used as a substitute for fossil fuel. Lignocellulose is the most abundant biomass resource for the production of fuel ethanol. However, the hydrolysis of lignocellulose requires high enzyme loading. In order to strengthen the process of enzyme hydrolysis of lignocellulose,surfactant-polyethylene glycol (PEG) was applied to the catalysis of lignocellulose into fermentable sugars. The effect of PEG on both the enzymatic hydrolysis and adsorption of cellulose were investigated. The addition of surfactant obviously facilitated enzymatic hydrolysis. In particular, upon addition of PEG4000, the enzyme catalytic efficiency increased by 51.06%. Meanwhile,the adsorption quantity of cellulase decreased by 11.25%. In addition, the mechanism of the effect of PEG on enzymatic hydrolysis and cellulase adsorption is discussed.

Study on steel plate shear walls with diagonal stiffeners by cross brace-strip model

Yuqing Yang,Zaigen Mu,Boli Zhu 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.1

Steel plate shear walls (SPSWs) are commonly utilized to provide lateral stiffness in high-rise structures. The simplified model is frequently used instead of the fine-scale model in the design of buildings with SPSWs. To predict the lateral strength of steel plate shear walls with diagonal stiffeners (DS-SPSWs), a simplified model is presented, namely the cross bracestrip model (CBSM). The bearing capacity and internal forces of columns for DS-SPSWs are calculated. In addition, a modification coefficient is introduced to account for the shear action of the thin plate. The feasibility of the CBSM is validated by comparing the numerical results with theoretical and experimental results. The numerical results from the CBSM and finescale model, which represent the bearing capacity of the DS-SPSW with varied stiffened plate dimensions, are in good accord with the theoretical values. The difference in bearing capacity between the CBSM and the fine-scale model is less than 1.35%. The errors of the bearing capacity from the CBSM are less than 5.67% when compared to the test results of the DS-SPSW. Furthermore, the shear and axial forces of CBSM agree with the results of the fine-scale model and theoretical analysis. As a result, the CBSM, which reflects the contribution of diagonal stiffeners to the lateral resistance of the SPSW as well as the effects on the shear and axial forces of the columns, can significantly improve the design accuracy and efficiency of buildings with DS-SPSWs.

Desire(盼)

Yuqing Ma 한국콘텐츠학회 2015 ICCC International Digital Design Invitation Exhib Vol.2015 No.12

Research on characterization method and influencing factors of sedimentation stability of magnetorheological fluid

Yuqing Li,YiPing Luo,Ying Wang,Jiao Luo,Yameng Chen 한국유변학회 2021 Korea-Australia rheology journal Vol.33 No.4

The sedimentation stability of Magnetorheological fluid (MRF) is one of the research hotspots in the academic field of magnetorheological science. Excellent sedimentation stability is of great significance for the preservation and application of MRF. Given many traditional methods of characterization of sedimentation stability, this paper proposes a new method to characterize the sedimentation stability of MRF based on the change of shear yield stress during the sedimentation process of MRF. Then, the key components of the selfmade MRF shear yield stress test device were introduced in detail, and three different surfactants containing dodecyl benzoate, polyethylene glycol and oleic acid were prepared. And then used the device to test their effects on the sedimentation stability of MRF. The results showed that oleic acid has the best effect on improving the sedimentation stability. Finally, the change law of shear yield stress of MRF in the next 90 days was predicted successfully by fitting experimental data based on the least square method. By comparing the test value and fitting value of 60-75 days, the error of the best fitting result were within 3%, this showed the reliability of the predicted results.

Acid Exposure Time > 6% Might Not Improve the Therapeutic Outcome in Chinese Gastroesophageal Reflux Disease Patients

( Yuqing Lin ),( Yuwen Li ),( Mengya Liang ),( Niandi Tan ),( Mengyu Zhang ),( Songfeng Chen ),( Yinglian Xiao ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2021 Journal of Neurogastroenterology and Motility (JNM Vol.27 No.1

Background/Aims There is less acid burden in Chinese gastroesophageal reflux disease (GERD) patients. However, the Lyon consensus proposed a higher threshold of acid exposure time (AET > 6%) for GERD. The aims are to apply the updated criteria in Chinese GERD patients and clarify its influence on clinical outcome. Methods Patients who were referred for both esophageal high-resolution manometry and 24-hour esophageal pH monitoring due to reflux symptoms were retrospectively screened. Those patients with AET > 4% was included and grouped into either AET 4-6% or AET > 6%. Their manometric profile, reflux profile, and response to proton pump inhibitors (PPIs) were evaluated. Adjunctive evidence proposed in the Lyon consensus was added in patients with AET 4-6% for therapeutic gain. Another group of patients (n = 144) with AET < 4% were included as non-GERD patients. Results In total, 151 patients (102 males) were included with 113 patients AET > 6% (74.9%). GERD patients with AET > 4% were with more male, older patients, and higher body mass index compared with non-GERD patients. Meanwhile, GERD patients were less competent in esophagogastric junction pressure. However, the manometric and reflux profile were similar between patients with AET > 6% and 4-6%. The response rate of PPI therapy was 64.6% and 63.2%, respectively, in groups of AET > 6% and 4-6% (P > 0.05). When adjunctive evidence was added in patients with AET 4-6%, no therapeutic gain was obtained. Conclusions The efficacy of PPI therapy was similar in patients with AET > 6% and 4-6%. The increase of the AET threshold did not influence the clinical outcome of Chinese GERD patients. (J Neurogastroenterol Motil 2021;27:55-62)

The Long Noncoding RNA NEAT1 Targets miR-34a-5p and Drives Nasopharyngeal Carcinoma Progression via Wnt/β-Catenin Signaling

Yuqing Ji,Man Wang,Xueshen Li,Fusheng Cui 연세대학교의과대학 2019 Yonsei medical journal Vol.60 No.4

Purpose: Long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) has been deemed an oncogene in many humancancers. However, the underlying mechanism of NEAT1 in nasopharyngeal carcinoma (NPC) progression remains largelyunclear. Materials and Methods: Quantitative real-time PCR assay was performed to assess the expression of NEAT1 and miR-34a-5p inNPC tissues and cells. Western blot analysis was used to observe cell epithelial to mesenchymal transition (EMT) and the activationof Wnt/β-catenin signaling in 5-8F cells. MiRNA directly interacting with NEAT1 were verified by dual-luciferase reporter assayand RNA immunoprecipitation. Cell proliferation ability was determined by CCK-8 assay, and cell migration and invasion capacitieswere assessed by transwell assays. An animal model was used to investigate the regulatory effect of NEAT1 on tumorgrowth in vivo. Results: Our data revealed that NEAT1 is upregulated, while miR-34a-5p is downregulated in NPC tissues and cell lines. NEAT1knockdown repressed tumor growth in vitro and in vivo. Additionally, we discovered that NEAT1 directly binds to miR-34a-5pand suppresses miR-34a-5p expression. Moreover, NEAT1 knockdown exerted suppression effects on cell proliferation, migration,invasion, and EMT by miR-34a-5p. NEAT1 knockdown blocked Wnt/β-catenin signaling via miR-34a-5p. Conclusion: Our study demonstrated that NEAT1 targets miR-34a-5p at least partly to drive NPC progression by regulating Wnt/β-catenin signaling, suggesting a potential therapeutic target for NPC.

Cobalt-Porphyrin Modified Three-Dimensional Graphene Hydrogel Electrode for High Performance Asymmetric Supercapacitors

Yuqing Song,Hongfei Wang,Lifeng Yan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.5

Three-dimensional (3D) graphene-based materials have attracted much attention in the field of supercapacitors for their large surface areas and fast electronic conductivity capability. Faradaic pseudo-capacitance materials inside the architecture can enlarge the electrochemical performance of the electrode. Additionally, metal porphyrins are negative electrode active materials for supercapacitors as they have potential high pseudo-capacitance, conductivity and N-doping. The design and preparation of the 3D cobalt-porphyrin modified graphene hydrogels (3D CoP/GHs) is an interesting topic. Here, we have fabricated the 3D CoP/GH by a two-step method. The composite electrode reaches a specific capacitance of 335 F g -1, twice that of pure GHs. At the same time, resistance of the electrode material decreases and the ion transfer is accelerated due to the addition of cobalt-porphyrin. After 10 000 cycles, the 3D CoP/GH maintains its stable specific capacitance retention of 94.11% indicating its excellent cycle life. The cycle life is much better than that of a hydrogel that has not been doped (81.63%) according to our previous work. Then we fabricated an asymmetrical supercapacitor which uses both the 3D CoP/GH and GH as the two electrodes (3D CoP/GHjjGH), and reaches an outstanding energy density of 30.40 Wh kg -1 at a current density of 1 A g -1 while the power density is 749.5 W kg -1.

Evaluation of the Differences of Myocardial Fibers between Acute and Chronic Myocardial Infarction: Application of Diffusion Tensor Magnetic Resonance Imaging in a Rhesus Monkey Model

Yuqing Wang,Wei Cai,Lei Wang,Rui Xia,Wei Chen,Jie Zheng,Fabao Gao 대한영상의학회 2016 Korean Journal of Radiology Vol.17 No.5

Objective: To understand microstructural changes after myocardial infarction (MI), we evaluated myocardial fibers of rhesus monkeys during acute or chronic MI, and identified the differences of myocardial fibers between acute and chronic MI. Materials and Methods: Six fixed hearts of rhesus monkeys with left anterior descending coronary artery ligation for 1 hour or 84 days were scanned by diffusion tensor magnetic resonance imaging (MRI) to measure apparent diffusion coefficient (ADC), fractional anisotropy (FA) and helix angle (HA). Results: Comparing with acute MI monkeys (FA: 0.59 ± 0.02; ADC: 5.0 ± 0.6 x 10-4 mm2/s; HA: 94.5 ± 4.4°), chronic MI monkeys showed remarkably decreased FA value (0.26 ± 0.03), increased ADC value (7.8 ± 0.8 x 10-4mm2/s), decreased HA transmural range (49.5 ± 4.6°) and serious defects on endocardium in infarcted regions. The HA in infarcted regions shifted to more components of negative left-handed helix in chronic MI monkeys (-38.3 ± 5.0°–11.2 ± 4.3°) than in acute MI monkeys (-41.4 ± 5.1°–53.1 ± 3.7°), but the HA in remote regions shifted to more components of positive right-handed helix in chronic MI monkeys (-43.8 ± 2.7°–66.5 ± 4.9°) than in acute MI monkeys (-59.5 ± 3.4°–64.9 ± 4.3°). Conclusion: Diffusion tensor MRI method helps to quantify differences of mechanical microstructure and water diffusion of myocardial fibers between acute and chronic MI monkey’s models.

Global Value Chains and China's Exports to High-income Countries

Yuqing Xing 한국국제경제학회 2016 International Economic Journal Vol.30 No.2

This paper argues that global value chains (GVCs) have functioned as a vehicle for ‘Made in China’ products to enter international markets, especially markets of high-income countries. The analysis of the paper focuses on China's processing exports, a subset of GVC activities. It demonstrates that, by participating in GVCs Chinese firms bundle processing exports with advanced technologies and globally recognized brands of lead firms, and then sell them to consumers of international markets through distribution networks of GVCs. Using panel data of bilateral processing exports covering more than 100 of China's trade partners, the paper shows empirically there exists a significantly positive correlation between the share of processing exports and the income of trading partners, implying that processing trade is an effective means for ‘Made in China’ products to enter high-income countries. The cross-country heterogeneity of processing exports also indicates China captures relatively more value added in its exports to low-income countries than to high-income countries.